As I look down on the reviews, no one has said anything about this particular thermostat controller. Although I am a fan and loyal customer Hort. Source, I have one of these units, (purchased from a local grow shop) and the thing is not accurate. Yes it does work, and gives you much better control over the environment, however the the temp on the display varies between 8-12 degrees higher than the actual temp. of the medium + there is no way to calibrate the temp. probe. Since it works like that, I just set it at 10-12 degrees higher than the temp I am trying to achieve. (i.e. set @ 84-86 to get 75degrees.) Anyone else have this problem?